Recovery of nitrogen and acetone from vinasses



Aug. 5, 1930. J. GUiLLlSSEN 1,772,078

RECOVERY OF NITROGEN AND ACETONE FROM VINASSES Filed Aug. 27, 192T Patented Aug. 1930 UNITED STATES I'OSEIPH GUILLISSEN, F BRUSSELS, BELGIUM,

ASSIGNOR TO UNION CHIMIQUE BELGE,

SOCIETE ANONYME, OF BRUSSELS, BELGIUM RECOVERY OF NITROGEN Application filed August 27, 1927, Serial No.

tillation with addition of an alkaline-earth metal base.

It has previously been proposed to carry out the said pyrogenous distillation in vacuo or under reduced pressure, such as an absolute pressure of about 60 millimetres of mercurv, and at a temperature of from 500 to 700 C.

The present invention has for its object the suppression of the drawbacks involved by a pyrogenous distillation when the latter is carried out under a very reduced pressure, more particularly of the difiiculties of construction and operation of the apparatus working under such a reduced pressure. Moreover, the invention enables to increase the output in the by-products which it is desired to obtain, reduces the duration of the treatment and allows of conducting the operation in a continuous manner.

This invention consists in subjecting the vinasses to a pyrogenous'distillation in the presence of an excess of an alkalineearth metal base in a current of non-oxidizing gases at a pressure approaching or higher than the atmospheric pressure and at a temperature below 600 C.

Particularly favourable results are obtained when the pyrogenous distillation is carried out in a current of nitrogen, or oxide of carbon, or hydrogen, or'inethane, these gases being saturated or not with water vapour;

The base used for the pyrogenous distillation is preferably lime and its amount pref erably exceeds per cent of the weight of vinasses subjected to distillation.

Another use is made as the gasedistillation, of obtained from the pyrogenous disusefulby-products: ketones, ammonia, am-

y ines, etc.

The accompanying drawing illustrates diagrammatically and characteristic feature of the pres- .ent invention is that :ous current suitable for the the gases "tillation ofgthe vinasses after recovery of the by way of example AND ACETONE FROM VINLASSES 215,943, and in Belgium September 21, 1926.

one mode of arrangement of apparati permitting to carry the invention into effect.

Referring to the drawing, A is the distillation oven or retort, B are refrigerating apparatus, C is a pump or exhauster, D is an absorbing apparatus, for acetone for 4 instance, E is the return piping of the gases to the distilling apparatus, F is a valve allowing the excess of gases produced to be sent to a gasholder G; H represents the feeding devices for the initial mixture and I rep- 365611135 the discharge apparatus for the resiues.

The latter are carbonaceous substances which can be used as a decolourizing agent.

It is seen from the accompanying drawing that the operation may be carried out in a continuous manner. 4

The mixing of vinasse to be treated and lime or the like is effected preferably before the distillation operation, and preferably at a temperature of 100 C. An alkaline-earth metal carbonate, such as calcium carbonate, or residues from a previous distillation, or a hygroscopic substance such as saw-dust, may be added together with the lime.

Example-4,000 kilos of vinasses at 40 B. are mixed with 700 kilos of lime and with 300 kilos of saw-dust or with 300 kilos ofresidues from a previous operation. The mixture thus obtained is subjected to a pyrogenous distillation J'by progressive heating inside a metallic retort provided with mechanical stirring means, until a temperature of about 350 C. is reached. During the whole operation, a circulation of washed gases obtained from the distilling operation itself is maintained, at a pressure s ightly higher than the atmospheric pressure.

80 or 90% of the nitrogen of the vinasse is recovered in the form of ammonia or of cyanurable amines, also 1.50% of acetone of boiling point lower than 65 6., 0.5% of higher ketones and a residue containing about 10% of a very light carbon having decolourizing properties.

ll claim:

1. A process for the recovery of nitrogen and acetone from vinasses, comprising su jecting the vinasses to a pyrogenous continu- 45 distilling ous distillation in a distilling apparatus in the presence of an excess of alkaline earth metal base (over 50% of the weight of vinasses) at a pressure substantially equal to 5 the atmospheric gressure and at a temperature below 600 thus producing a distillate, subjecting the distillate to a treatment for the recovery of nitrogen and acetone and for the separation of non-oxidizing gases at a comparatively low temperature, sending the non-oxidizing gases at a comparatively low temperature back-into the distilling apparatus, as set forth.

2. A process for the recovery of nitrogen and acetone from vinasses, comprising subjecting the vinasses to a pyrogenous continuous distillation in a distilling apparatus in the presence of an excess of alkaline earth metal base (over 50% of the weight of vinasses') at a pressure substantially equal to the atmospheric pressure and at a temperature below 600 0., thus producing a distillate, subjecting the distillate to a treatment for the recovery of nitrogen and acetone and 'for the separation of non-oxidizing gases at a: comparatively low temperature, saturating the gases with water vapour, and sending them at a comparatively low temperature back into the distilling apparatus, as set forth.

'3. A process for the recovery of nitrogen and acetonefrom vinasses, comprising subjecting the vinasses to a pyrogenous continuous distillation in a distilling apparatus in 85 the presence of an excess of alkaline. earth metal base (over of the weight of vinasses), and" of a hy oscopic substance, thus producing a distillate, subjecting the distillate to a treatment'for the recovery of 4 nitrogen and acetone and for the separation of non-oxidizing gases at a comparativelylow temperature, saturating the gases with water vapour,- and sending them at a comparatively low temperature back into the apparatus, 'as set forth. JOSEPH GUILLISSEN. 

